This invention relates to a system and method for producing instantaneous x-ray pictures of a subject by generating a narrow, sweeping beam of x-rays to irradiate a subject, and detecting the x-rays by means of an x-ray sensitive video pickup tube which produces a video signal for presentation of an instantaneous picture on a video monitor, or for recording.
A principal object of this invention is to provide an x-ray imaging system and method wherein the exposure of the subject to radiation is substantially reduced.
Another object of this invention is to provide an x-ray imaging system and method for producing an instantaneous video image of the subject.
Another object of this invention is to provide an x-ray imaging system and method which can produce a single picture, sequential pictures, or continuous pictures without film.
Still another object of this invention is to provide an x-ray imaging system and method which produces a video signal of the x-ray picture enabling instantaneous video presentation and/or recording of the video signal on magnetic tape or on video discs for later selective presentation.
A further object of this invention is to provide an x-ray imaging system and method producing an instantaneous and varying video representation of a moving subject.
A still further object of this invention is to provide a system and method for producing improved x-ray images of subjects, whether human or inanimate.
Another object of this invention is to provide an x-ray imaging system and method wherein a very narrow x-ray beam is produced to sweep the subject in a controlled scan, and wherein the sweeping x-ray beam is detected on an x-ray sensitive video pickup tube by a sweeping electron beam controlled in synchronism with the sweeping x-ray beam.
Still another object of this invention is to provide an x-ray imaging system and method for producing instantaneous video images having very high resolution.
These objects are achieved in a system and method which includes an x-ray generating tube for generating a controlled narrow sweeping beam of x-rays, and a video pickup tube for detecting the x-radiation. The x-ray generating tube includes means for generating a focused high energy electron beam; an anode having an enlarged face disposed to be impinged by the electron beam; a system for deflecting the electron beam to sweep the anode face producing a moving focal spot; and means defining a shielded point-source window in the tube envelope. The anode face is oriented relative to the generated electron beam and to the window, to direct generated x-rays from the moving focal spot to the window, thereby radiating a narrow moving beam of x-rays. The video pickup tube includes a face plate having a mosaic of x-ray-sensitive globules responsive to x-radiation to produce an electric image corresponding to the density of x-rays passing through an irradiated subject; means for producing a focused electron beam directed to the face plate; and means for deflecting the electron beam to sweep said face plate. Control circuit means include means for synchronizing the sweep of the video pickup tube electron beam and the sweep of the x-ray generating tube electron beam whereby the video pickup tube produces a video output signal for feeding a video monitor to produce the generated x-ray picture.
The advantages of the invention as well as additional objects thereof will be understood more fully from the following description when read in connection with the accompanying drawing.